Using non-parametric Bayes shrinkage to assess relationships between multiple environmental and social stressors and neonatal size and body composition in the Healthy Start cohort

Background: Both environmental and social factors have been linked to birth weight and adiposity at birth, but few studies consider the effects of exposure mixtures. Our objective was to identify which components of a mixture of neighborhood-level environmental and social exposures were driving associations with birth weight and adiposity at birth in the Healthy Start cohort. Methods: Exposures were assessed at the census tract level and included air pollution, built environment characteristics, and socioeconomic status. Prenatal exposures were assigned based on address at enrollment. Birth weight was measured at delivery and adiposity was measured using air displacement plethysmography within three days. We used non-parametric Bayes shrinkage (NPB) to identify exposures that were associated with our outcomes of interest. NPB models were compared to single-predictor linear regression. We also included generalized additive models (GAM) to assess nonlinear relationships. All regression models were adjusted for individual-level covariates, including maternal age, pre-pregnancy BMI, and smoking. Results: Results from NPB models showed most exposures were negatively associated with birth weight, though credible intervals were wide and generally contained zero. However, the NPB model identified an interaction between ozone and temperature on birth weight, and the GAM suggested potential non-linear relationships. For associations between ozone or temperature with birth weight, we observed effect modification by maternal race/ethnicity, where effects were stronger for mothers who identified as a race or ethnicity other than non-Hispanic White. No associations with adiposity at birth were observed. Conclusions: NPB identified prenatal exposures to ozone and temperature as predictors of birth weight, and mothers who identify as a race or ethnicity other than non-Hispanic White might be disproportionately impacted. However, NPB models may have limited applicability when non-linear effects are present. Future work should consider a two-stage approach where NPB is used to reduce dimensionality and alternative approaches examine non-linear effects

Synthesis of (8E,10Z)-tetradeca-8,10-dienal, sex pheromone of horse chestnut leafminer (Cameraria ohridella), and all its geometrical isomers

(8E,10Z)-Tetradeca-8,10-dienal (1a), sex pheromone of the horse chestnut leaf miner (Cameraria ohridella; Lepidoptera, Gracillariidae), and its geometrical isomers (1b-1d) were efficiently synthesized using tetrakis(triphenylphosphine)palladium catalyzed cross-coupling reactions of alk-1-ynes or alkenyl alanes with corresponding vinyl iodides. The stereoisomeric purity of obtained tetradecadienals 1a-1d was higher than 95% (GC). Relative electroantennographic (EAG) activities of the prepared compounds la-ld elicited on male antennae supported the previously published identification of the C. ohridella sex pheromone

New potential inhibitors of pheromonal attraction in the oriental fruit moth, Cydia molesta

New analogues of (Z)-dodec-8-en-1-yl acetate (Z8-12:OAc, 1), the main sex pheromone component of the Oriental fruit moth, Cydia molesta, were designed by formally transferring the terminal propyl group from the C-9 to the C-7 position to form vinyl-branched (2, 3) or, after isomerization, ethylidene-branched 4) structures and by replacing the -CH=CH- grouping by the -S-CH2- moiety (5, 6). Their biological activities were studied both electrophysiologically and behaviourally (laboratory mating and wind tunnel experiments). All the structural modifications resulted in analogues whose electroantennographic activities were lower than that of 1 following the order 1 much greater than 6 approximate to 5 much greater than 2 approximate to 4 approximate to 3. The single sensillum recording activities indicated that all the analogues stimulate the same Z8-12:OAc receptor neurone, In behavioural experiments, the analogues were generally found to reduce the ability of males to find a pheromone source, however, to different degrees. The highest inhibitory effect (90%) was observed for the thia analogues 5 and 6. The results support the view that the inhibitory properties of the analogues should not be entirely associated with their pheromone-mimicking capabilities

Biotransformations of gamma-methyl-beta-ketosulfones:stereoselectivity of 3-methyl-1-(phenylsulfonyl)hexan-2-one reductions by various yeasts

The stereoselectivity of the reduction of rac-3-methyl1-(phenylsulfonyl)hexan-2-one (1) to 3-methyl1-(phenylsulfonyl)hexan-2-ol (2) diastereomers by more than 20 yeasts was studied. Reduction of carbonyl group in 1 proceeds with a high Re-face enantioselectivity: Candida guillermondii (98.9% e.e.), C. zeylanoides (>99.9%), and Kloeckera apiculata (99.6%), respectively and the (R)-1 enantiomer usually reacted faster. The enantioselectivity was determined by GC on chiral cyclodextrine phases and absolute configurations of products were assigned by NMR spectroscopy and a chemical correlation. Copyright (C) 1996 Elsevier Science Lt

New mimics of the acetate function in pheromone-based attraction

Several analogues of (Z)-8-dodecenyl acetate (la), the major pheromone component of the Oriental fruit moth, Cydia molesta, with chloroformate and lactone functional groups in place of the acetate moiety, were synthesized and investigated for their biological activity at four evaluation levels, i.e. by electroantennography (EAG), electrosensillography (ESG), short-range sexual stimulation and activation in the flight-tunnel. We found very strict requirements on the shape as well as on the electron distribution of the acetate group for a productive interaction with the receptor. The behavioral results showed that, among the analogues investigated, the chloroformate lb, alken-4-olide 2a and also dodecyl acetate (lc) possess significant (60-85%) inhibitory activities. Based on electrophysiological evidence demonstrating that (i) only lb is competing with the major pheromone component la for the same receptor sites on the male antennal sensilla, (ii) lc elicits moderate EAG but no ESG responses and (iii) 2a does not produce any electrophysiologicai response at all, three possible inhibitory mechanisms by which these analogues are acting could be distinguished